https://backpack.tf/profiles/76561198024925599#!/compare/1497398400/1497484800 - a little over 2 months old, and sold for 29 keys

forgot to mention in the previous suggestion but your seller at 25 is duped.

29-33 could work here as a conservative drop assuming 22 and 23 sold relatively fast since the sale at 22 was the same hat that resold on marketplace.tf for 33 and looking at the sellers outpost for the 23 key sale, he most probably sold it quickly. (also to note there is a buyer at 21 which makes these seem a little on the low-side)